content: /*
   * Copyright 2017 David Karnok
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package hu.akarnokd.reactive4javaflow.impl.operators;
  
  import hu.akarnokd.reactive4javaflow.*;
  import hu.akarnokd.reactive4javaflow.functionals.*;
  import hu.akarnokd.reactive4javaflow.fused.ConditionalSubscriber;
  import hu.akarnokd.reactive4javaflow.impl.EmptySubscription;
  import hu.akarnokd.reactive4javaflow.processors.MulticastProcessor;
  
  import java.util.Objects;
  import java.util.concurrent.Flow;
  
  public final class FolyamPublish<T, R> extends Folyam<R> {
  
      final Folyam<T> source;
  
      final CheckedFunction<? super Folyam<T>, ? extends Flow.Publisher<? extends R>> handler;
  
      final int prefetch;
  
      public FolyamPublish(Folyam<T> source, CheckedFunction<? super Folyam<T>, ? extends Flow.Publisher<? extends R>> handler, int prefetch) {
          this.source = source;
          this.handler = handler;
          this.prefetch = prefetch;
      }
  
      @Override
      protected void subscribeActual(FolyamSubscriber<? super R> s) {
          MulticastProcessor<T> mp = new MulticastProcessor<>(prefetch);
          Flow.Publisher<? extends R> p;
          try {
              p = Objects.requireNonNull(handler.apply(mp), "The handler returned a null Flow.Publisher");
          } catch (Throwable ex) {
              EmptySubscription.error(s, ex);
              return;
          }
  
          if (s instanceof ConditionalSubscriber) {
              p.subscribe(new PublishConditionalSubscriber<>((ConditionalSubscriber<? super R>)s, mp));
          } else {
              p.subscribe(new PublishSubscriber<>(s, mp));
          }
  
          source.subscribe(mp);
      }
  
      static final class PublishSubscriber<R> implements FolyamSubscriber<R>, Flow.Subscription {
  
          final FolyamSubscriber<? super R> actual;
  
          final AutoDisposable mainSource;
  
          Flow.Subscription upstream;
  
          PublishSubscriber(FolyamSubscriber<? super R> actual, AutoDisposable mainSource) {
              this.actual = actual;
              this.mainSource = mainSource;
          }
  
          @Override
          public void onSubscribe(Flow.Subscription subscription) {
              upstream = subscription;
              actual.onSubscribe(this);
          }
  
          @Override
          public void onNext(R item) {
              actual.onNext(item);
          }
  
          @Override
          public void onError(Throwable throwable) {
              actual.onError(throwable);
              mainSource.close();
          }
  
          @Override
          public void onComplete() {
              actual.onComplete();
              mainSource.close();
          }
  
          @Override
          public void request(long n) {
              upstream.request(n);
          }
  
          @Override
          public void cancel() {
              upstream.cancel();
              mainSource.close();
          }
      }
  
  
      static final class PublishConditionalSubscriber<R> implements ConditionalSubscriber<R>, Flow.Subscription {
  
          final ConditionalSubscriber<? super R> actual;
  
          final AutoDisposable mainSource;
  
          Flow.Subscription upstream;
  
          PublishConditionalSubscriber(ConditionalSubscriber<? super R> actual, AutoDisposable mainSource) {
              this.actual = actual;
              this.mainSource = mainSource;
          }
  
          @Override
          public void onSubscribe(Flow.Subscription subscription) {
              upstream = subscription;
              actual.onSubscribe(this);
          }
  
          @Override
          public void onNext(R item) {
              actual.onNext(item);
          }
  
          @Override
          public boolean tryOnNext(R item) {
              return actual.tryOnNext(item);
          }
  
          @Override
          public void onError(Throwable throwable) {
              actual.onError(throwable);
              mainSource.close();
          }
  
          @Override
          public void onComplete() {
              actual.onComplete();
              mainSource.close();
          }
  
          @Override
          public void request(long n) {
              upstream.request(n);
          }
  
          @Override
          public void cancel() {
              upstream.cancel();
              mainSource.close();
          }
      }
  }
  